Yep he was a witniss against Willem holleerder. Willem Holleeder was the one who kidnapped Freddy Heiniken head of the heiniken enterprise in november 1981 and after he was conviced for that and did his time he actually climbed in the underworld and eventually became head of the biggest crimi organisation in the netherlands. Abraham being a lawyer got involved after his client Willem endstra got gunned down in the streets of amsterdam and was asked to became witniss in the case against willem holleeder. He eventually got into a witness protection program but stepped out on his own dissision and went back to live in amsterdam where he was found dead a week after testifieing when he was found dead in the shower on an overdose of MDMA(XTC) and alchohol. It is believed that his brazilian girlfriend who had ties with willem holleeder was somehow responsible fore his death and that the drugs where supplies by his own son.
Here is a picture of him when observered by the dutch crimi intellegance service with his client willem endsta who some believed to be a gangser himself
The man who most likely ordere the hit.
Let me finish by saying that Abraham (Bram Zeegers) was one of the good guys not the bad guys and the wrong place and the wrong time.