BUFFALO, Minn. (AP) — Authorities say a tip from an ex-wife pointed them to a Sartell man suspected in a string of armed robberies along Interstate 94 from the St. Cloud area to the Minneapolis suburbs.

Police on Wednesday released a security video after a masked man robbed a Burger King in Maple Grove. The ex-wife of Douglas Wayne Gravelle Jr., 34, saw the video on the news and told police he wore the same clothes at a child support hearing, according to charges filed Friday. She also said he’s addicted to prescription drugs and unemployed.

Gravelle was being held in the Wright County Jail on charges of aggravated robbery and kidnapping. His bail was set at $500,000. More charges are expected at his next court appearance Tuesday.

Maple Grove Police Capt. Keith Terlinden said some items seized at Gravelle’s home Thursday night tie him to the robberies.

Gravelle lived with his father, Douglas Gravelle Sr., who said his son should be presumed innocent until proven guilty.

“This is really embarrassing,” the retired corrections officer said. “I feel I am a failure as a parent and as a citizen. I am going through a mixed bag of emotions. I am staying as neutral as I can, not being judgmental. He has his demons. I have my demons. Every person has their own demons. You have to learn how to deal with them.”

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