The brazen escapes of three suspected murderers in recent days in separate incidents are casting scrutiny on law enforcement's ability to keep prisoners under lock and key, according to experts.
While two of the escapees -- both the subjects of massive manhunts -- were captured, the third -- Michael Burham, who authorities described as a "self-taught survivalist" and a former Army reserve sergeant -- remained on the run Wednesday as a reward for information leading to his capture grew to $19,500. He is suspected to be armed and dangerous, according to authorities, hiding in the northeast Pennsylvania woods six days after breaking out of the Warren County Jail in Pennsylvania.
"Based on everything I've seen, I do believe he is receiving help," Lt. Col. George Bivens of the Pennsylvania State Police said of Burham at a news conference Tuesday afternoon.
And on Monday night, Indiana Sheriff's Deputy John Drum, 61, was allegedly killed by an inmate attempting to escape, officials said. Orlando Mitchell, the 34-year-old inmate, allegedly assaulted Drum as the deputy drove him from a hospital to the Indianapolis Adult Detention Center. The inmate, who is facing charges of killing his girlfriend in 2022, allegedly stole a sheriff's department transport wagon and crashed it in an attempt to get away, officials said. He was quickly taken into custody.
"It's opportunity and they're taking it," Robert Boyce, a former Chief of Detectives for the New York Police Department, said of what drives many prisoners to attempt an escape from custody.
Boyce, an ABC News contributor, also said that many escapes occur during the summer, a possible explanation for the recent string of inmates bolting.
Bryce Peterson, an adjunct professor at John Jay College of Criminal Justice, told ABC News that many of the escapees also appear to have the motivation to run, saying inmates serving long sentences or facing serious charges like murder "are the most likely to escape."
"It just comes down to when they have a chance to do it," Peterson told ABC News.
Peterson, also a research scientist for the nonprofit Center for Justice Research and Innovation at the Center for Naval Analysis, co-authored a 2016 report that analyzed 611 inmates involved in 503 escape incidents at 398 different U.S. lock-up facilities.
"Our findings indicate that escapes from jail are a frequent, yet overlooked, phenomenon. The results also challenge the misperception that escapes are often sensational and violent events," Peterson's report, "Escape from Correctional Custody: A New Examination of an Old Phenomenon," concluded.
Peterson noted that most escapes are "very mundane and routine," unlike the Hollywood version of prisoners spending months secretly tunneling out of prison like in the 1994 movie "The Shawshank Redemption."
"In fact, the vast majority of escapes are simply what we call 'walkaways,' in which someone who is in a minimum-security facility where there's no walls, no fences, or very, very minimal kind of external perimeter security, simply walk off the facility," Peterson said.
In the most elaborate recent escapes, authorities said Burham is suspected of breaking out of jail by climbing atop exercise equipment in a recreation yard and going through a metal-grated roof. Burham then used bed sheets tied together to lower himself to the ground, where he fled on foot, officials said.
"When there is more motivation and more planning that occurs, it's typically pretty simple," Peterson said. "There have been real cases of people tunneling through walls and that kind of thing. It's just not nearly as common."
The Warren County Board of Commissioners announced Wednesday morning that in conjunction with the state Prison Board, it has reviewed data associated with Burham's escape and ordered immediate safety changes to the Warren County Jail in an attempt to prevent further escapes. The modifications, according to the commissioners, include fortifying the 40-foot-by-40-foot caged recreation yard's roof on the top floor of the facility "with deterrents and safety measures" and replacing exercise equipment to eliminate access to higher positions in the facility.
"The Commissioners expect the immediate structural fixes to be completed before the end of the week," the board said in a statement. "Several longer-term upgrades will begin immediately and be completed in the next few weeks."
Peterson said his research also shows that most escapes happen at county jails instead of federal and state prisons.
"Jails often are older facilities, or even if they're not older, they're not as well kept up sometimes," Peterson said. "Most jails are very small; they have small budgets. They're run through counties; they have more staffing shortages and bigger staffing issues. Although state prisons also have staffing shortages, county jails have a very hard time with staffing, especially right now."
Besides the study he co-wrote with his John Jay colleague Jeff Mellow, a professor of criminal justice, Peterson said very little research or national data on escapes exists.
"One of the consistent findings we had from the work that we did ... specifically found that escapes that occurred during transportation are the most likely to result in violence," Peterson said.
Inmate Chadwick Shane Mobley, 42, is alleged to have fled from authorities in Montana on Sunday. He was being taken to Michigan to face charges in the 2011 slaying of a 20-year-old woman, officials said.
Employees of a private transport company contracted by the U.S. Marshals Service were driving Mobley from the Lincoln County Jail in Libby, Montana, to Michigan on Sunday when he managed to slip out of his handcuffs and ankle shackles, authorities said. According to the Sanders County Sheriff's Office, he bolted from custody around 10 a.m. local time at a gas station in Plains, Montana. Mobley was located on Monday evening in Plains and captured, authorities said.
An investigation by The Marshal Project, a nonprofit news organization covering the U.S. criminal justice system, found at least 60 prisoners escaped from private extradition vehicles between 2000 and 2018, including one who later stabbed a police officer after escaping.
MORE: California murder suspect Eric Abril, who escaped from hospital, captured following massive manhunt"There's very little oversight," Peterson said of the private inmate transport companies. "It's not clear what their training policies always are, what credentials the staff have to transport individuals. I think that's certainly an area that we should be looking at if we're trying to curb escapes, and especially to reduce the amount of violence that occurs during the escapes."
He said multiple inmates have also escaped while under guard at medical facilities over the years.
On Sunday, California inmate Eric Abril, suspected in a hostage-taking homicide and shootout with police, escaped from a medical facility in the Sacramento suburb of Roseville, where he was supposed to be under 24-hour surveillance, Placer County Sheriff Wayne Woo said at a news conference. The 35-year-old fugitive was captured Monday after being spotted in a residential area in Rocklin, California, roughly 6 miles from where he escaped, officials said.
"When you're in a hospital, unless you can sneak out of a window or something like that, you're under guard 24/7. That's a situation that often leads to violence, or at least compared to people who are breaking out from inside facilities," Peterson said.
MORE: Escaped suspect in Michigan murder taken back into custody in MontanaWhile no injuries were reported in Abril's escape, a deputy briefly chased Abril on foot but lost him.
Peterson said his research also shows that it's "very rare" for escapees to remain at large for more than a few days before they are caught.
"From the best we can tell from other research that's been done, although it's very outdated, at least 90% of people tend to get recaptured. And of the people that don't get recaptured, who spend more time out or who stay out, either permanently or for a very long time, it's typically because there are not people looking for them, to be honest," Peterson said.
Peterson added: "For people facing very serious charges or people who are convicted of very serious charges, they are almost certainly going to get caught at some point. It's usually within a few days, sometimes up to a week or two. There are the cases where people stay out of custody for much longer than that, but it is rare."