A suspect remains at large and a bank customer was arrested for tampering with evidence in connection with a bank robbery in Marina del Rey Nov. 2, Los Angeles County Sheriff’s Department officials said.

Deputies from the Marina del Rey Sheriff’s Station were called at 10:20 a.m. to a Bank of America in the 4700 block of Admiralty Way, where a male suspect had allegedly robbed the bank using a demand note. The suspect fled on foot with an undisclosed amount of cash prior to the arrival of responding deputies.

The suspect is described as a Hispanic man, 18 to 20 years old, approximately 5-foot-8, 140 to 145 pounds, with long dark hair, deputies said. He was wearing a black and brown striped beanie, a black and blue plaid long sleeve shirt, blue sweat pants and white tennis shoes.

During the subsequent investigation, deputies and agents from the Federal Bureau of Investigation questioned witnesses in the bank. Within minutes, a woman told deputies she had just seen a suspicious man in the parking lot who allegedly discarded a stack of money after it exploded in his pocket. The woman provided a description and license plate number of the vehicle the man drove away in.

Deputies immediately responded to the registered owner’s address in the 13900 block of Marquesas Way in Marina del Rey, where they detained a man later identified as Stephen Mullen, Sheriff’s officials said.

Investigators determined that Mullen had located a decoy “bait money” dye pack that was discarded by the bank robber outside of the bank. Mullen allegedly placed the bait money in his pocket and re-entered the bank when responding deputies arrived, but he reportedly did not mention this to the deputies or investigators on the scene, deputies said.

When Mullen left the bank, the dye pack exploded in his pocket, at which point he discarded the bag in the parking lot and drove home, deputies said.

Sheriff’s deputies arrested Mullen and booked him for tampering with evidence. The investigation is ongoing, and it does not appear that Mullen was involved in the initial robbery of the bank, deputies said.

Anyone with additional information regarding this case is encouraged to contact Sheriff’s Department Marina del Rey Station detectives at (310) 482-6000.